The Collaborative International Dictionary of English v.0.48:
Covin \Cov"in\ (k?v"?n), n. [OF. covine, covaine, fr. covenir to agree. See Covenant.] 1. (Law) A collusive agreement between two or more persons to prejudice a third. [1913 Webster] 2. Deceit; fraud; artifice. [Obs.] --Chaucer. [1913 Webster]